mirror of
https://github.com/sheumann/hush.git
synced 2024-12-22 14:30:31 +00:00
hush: fix glob() abuse. Code was making unfounded assumptions how
glob() works, and it broke horribly on specific uclibc config.
This commit is contained in:
Denis Vlasenko
parent
ff0976248a
commit
d65ea39ffc
179
shell/hush.c
179
shell/hush.c
@ -246,7 +246,7 @@ struct redir_struct {
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redir_type type; /* type of redirection */
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int fd; /* file descriptor being redirected */
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int dup; /* -1, or file descriptor being duplicated */
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glob_t glob_word; /* *word.gl_pathv is the filename */
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char **glob_word; /* *word.gl_pathv is the filename */
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};
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struct child_prog {
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@ -256,7 +256,7 @@ struct child_prog {
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smallint subshell; /* flag, non-zero if group must be forked */
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smallint is_stopped; /* is the program currently running? */
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struct redir_struct *redirects; /* I/O redirections */
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glob_t glob_result; /* result of parameter globbing */
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char **glob_result; /* result of parameter globbing */
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struct pipe *family; /* pointer back to the child's parent pipe */
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//sp counting seems to be broken... so commented out, grep for '//sp:'
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//sp: int sp; /* number of SPECIAL_VAR_SYMBOL */
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@ -503,9 +503,9 @@ static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN;
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static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN;
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static int run_pipe_real(struct pipe *pi);
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/* extended glob support: */
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static int globhack(const char *src, int flags, glob_t *pglob);
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static char **globhack(const char *src, char **strings);
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static int glob_needed(const char *s);
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static int xglob(o_string *dest, int flags, glob_t *pglob);
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static int xglob(o_string *dest, char ***pglob);
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/* variable assignment: */
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static int is_assignment(const char *s);
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/* data structure manipulation: */
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@ -548,6 +548,58 @@ static struct variable *get_local_var(const char *name);
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static int set_local_var(char *str, int flg_export);
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static void unset_local_var(const char *name);
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static char **add_strings_to_strings(int need_xstrdup, char **strings, char **add)
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{
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int i;
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unsigned count1;
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unsigned count2;
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char **v;
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v = strings;
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count1 = 0;
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if (v) {
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while (*v) {
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count1++;
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v++;
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}
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}
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count2 = 0;
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v = add;
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while (*v) {
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count2++;
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v++;
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}
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v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
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v[count1 + count2] = NULL;
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i = count2;
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while (--i >= 0)
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v[count1 + i] = need_xstrdup ? xstrdup(add[i]) : add[i];
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return v;
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}
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/* 'add' should be a malloced pointer */
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static char **add_string_to_strings(char **strings, char *add)
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{
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char *v[2];
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v[0] = add;
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v[1] = NULL;
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return add_strings_to_strings(0, strings, v);
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}
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static void free_strings(char **strings)
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{
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if (strings) {
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char **v = strings;
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while (*v)
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free(*v++);
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free(strings);
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}
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}
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/* Table of built-in functions. They can be forked or not, depending on
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* context: within pipes, they fork. As simple commands, they do not.
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* When used in non-forking context, they can change global variables
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@ -1067,16 +1119,14 @@ static void b_reset(o_string *o)
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{
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o->length = 0;
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o->nonnull = 0;
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if (o->data != NULL)
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*o->data = '\0';
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if (o->data)
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o->data[0] = '\0';
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}
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static void b_free(o_string *o)
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{
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b_reset(o);
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free(o->data);
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o->data = NULL;
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o->maxlen = 0;
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memset(o, 0, sizeof(*o));
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}
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/* My analysis of quoting semantics tells me that state information
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@ -1256,13 +1306,13 @@ static int setup_redirects(struct child_prog *prog, int squirrel[])
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struct redir_struct *redir;
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for (redir = prog->redirects; redir; redir = redir->next) {
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if (redir->dup == -1 && redir->glob_word.gl_pathv == NULL) {
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if (redir->dup == -1 && redir->glob_word == NULL) {
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/* something went wrong in the parse. Pretend it didn't happen */
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continue;
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}
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if (redir->dup == -1) {
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mode = redir_table[redir->type].mode;
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openfd = open_or_warn(redir->glob_word.gl_pathv[0], mode);
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openfd = open_or_warn(redir->glob_word[0], mode);
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if (openfd < 0) {
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/* this could get lost if stderr has been redirected, but
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bash and ash both lose it as well (though zsh doesn't!) */
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@ -2024,6 +2074,7 @@ static int run_list_real(struct pipe *pi)
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#if ENABLE_HUSH_LOOPS
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if (rword == RES_FOR && pi->num_progs) {
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if (!for_lcur) {
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/* first loop through for */
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/* if no variable values after "in" we skip "for" */
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if (!pi->next->progs->argv)
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continue;
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@ -2036,17 +2087,16 @@ static int run_list_real(struct pipe *pi)
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}
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free(pi->progs->argv[0]);
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if (!*for_lcur) {
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/* for loop is over, clean up */
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free(for_list);
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for_lcur = NULL;
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flag_rep = 0;
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pi->progs->argv[0] = for_varname;
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pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
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continue;
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}
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/* insert next value from for_lcur */
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/* vda: does it need escaping? */
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pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
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pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0];
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}
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if (rword == RES_IN)
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continue;
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@ -2149,8 +2199,8 @@ static int free_pipe(struct pipe *pi, int indent)
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for (a = 0, p = child->argv; *p; a++, p++) {
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debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
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}
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globfree(&child->glob_result);
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child->argv = NULL;
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free_strings(child->glob_result);
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child->glob_result = NULL;
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} else if (child->group) {
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debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
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ret_code = free_pipe_list(child->group, indent+3);
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@ -2162,9 +2212,10 @@ static int free_pipe(struct pipe *pi, int indent)
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debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip);
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if (r->dup == -1) {
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/* guard against the case >$FOO, where foo is unset or blank */
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if (r->glob_word.gl_pathv) {
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debug_printf_clean(" %s\n", r->glob_word.gl_pathv[0]);
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globfree(&r->glob_word);
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if (r->glob_word) {
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debug_printf_clean(" %s\n", r->glob_word[0]);
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free_strings(r->glob_word);
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r->glob_word = NULL;
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}
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} else {
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debug_printf_clean("&%d\n", r->dup);
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@ -2224,80 +2275,79 @@ static int run_list(struct pipe *pi)
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* string into the output structure, removing non-backslashed backslashes.
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* If someone can prove me wrong, by performing this function within the
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* original glob(3) api, feel free to rewrite this routine into oblivion.
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* Return code (0 vs. GLOB_NOSPACE) matches glob(3).
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* XXX broken if the last character is '\\', check that before calling.
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*/
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static int globhack(const char *src, int flags, glob_t *pglob)
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static char **globhack(const char *src, char **strings)
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{
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int cnt = 0, pathc;
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int cnt;
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const char *s;
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char *dest;
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char *v, *dest;
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for (cnt = 1, s = src; s && *s; s++) {
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if (*s == '\\') s++;
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cnt++;
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}
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dest = xmalloc(cnt);
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if (!(flags & GLOB_APPEND)) {
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pglob->gl_pathv = NULL;
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pglob->gl_pathc = 0;
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pglob->gl_offs = 0;
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pglob->gl_offs = 0;
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}
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pathc = ++pglob->gl_pathc;
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pglob->gl_pathv = xrealloc(pglob->gl_pathv, (pathc+1) * sizeof(*pglob->gl_pathv));
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pglob->gl_pathv[pathc-1] = dest;
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pglob->gl_pathv[pathc] = NULL;
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v = dest = xmalloc(cnt);
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for (s = src; s && *s; s++, dest++) {
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if (*s == '\\') s++;
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*dest = *s;
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}
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*dest = '\0';
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return 0;
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return add_string_to_strings(strings, v);
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}
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/* XXX broken if the last character is '\\', check that before calling */
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static int glob_needed(const char *s)
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{
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for (; *s; s++) {
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if (*s == '\\') s++;
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if (strchr("*[?", *s)) return 1;
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if (*s == '\\')
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s++;
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if (strchr("*[?", *s))
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return 1;
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}
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return 0;
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}
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static int xglob(o_string *dest, int flags, glob_t *pglob)
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static int xglob(o_string *dest, char ***pglob)
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{
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int gr;
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/* short-circuit for null word */
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/* we can code this better when the debug_printf's are gone */
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if (dest->length == 0) {
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if (dest->nonnull) {
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/* bash man page calls this an "explicit" null */
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gr = globhack(dest->data, flags, pglob);
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debug_printf("globhack returned %d\n", gr);
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} else {
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*pglob = globhack(dest->data, *pglob);
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}
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return 0;
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}
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} else if (glob_needed(dest->data)) {
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gr = glob(dest->data, flags, NULL, pglob);
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if (glob_needed(dest->data)) {
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glob_t globdata;
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int gr;
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memset(&globdata, 0, sizeof(globdata));
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gr = glob(dest->data, 0, NULL, &globdata);
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debug_printf("glob returned %d\n", gr);
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if (gr == GLOB_NOMATCH) {
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/* quote removal, or more accurately, backslash removal */
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gr = globhack(dest->data, flags, pglob);
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debug_printf("globhack returned %d\n", gr);
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}
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} else {
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gr = globhack(dest->data, flags, pglob);
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debug_printf("globhack returned %d\n", gr);
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}
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if (gr == GLOB_NOSPACE)
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bb_error_msg_and_die("out of memory during glob");
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if (gr == GLOB_NOMATCH) {
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debug_printf("globhack returned %d\n", gr);
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/* quote removal, or more accurately, backslash removal */
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*pglob = globhack(dest->data, *pglob);
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return 0;
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}
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if (gr != 0) { /* GLOB_ABORTED ? */
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bb_error_msg("glob(3) error %d", gr);
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}
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if (globdata.gl_pathv && globdata.gl_pathv[0])
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*pglob = add_strings_to_strings(1, *pglob, globdata.gl_pathv);
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/* globprint(glob_target); */
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globfree(&globdata);
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return gr;
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}
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*pglob = globhack(dest->data, *pglob);
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return 0;
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}
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/* expand_strvec_to_strvec() takes a list of strings, expands
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@ -2775,7 +2825,7 @@ static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
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}
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redir = xzalloc(sizeof(struct redir_struct));
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/* redir->next = NULL; */
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/* redir->glob_word.gl_pathv = NULL; */
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/* redir->glob_word = NULL; */
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if (last_redir) {
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last_redir->next = redir;
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} else {
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@ -2919,8 +2969,8 @@ static int reserved_word(o_string *dest, struct p_context *ctx)
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static int done_word(o_string *dest, struct p_context *ctx)
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{
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struct child_prog *child = ctx->child;
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glob_t *glob_target;
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int gr, flags = 0;
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char ***glob_target;
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int gr;
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debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child);
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if (dest->length == 0 && !dest->nonnull) {
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@ -2942,11 +2992,9 @@ static int done_word(o_string *dest, struct p_context *ctx)
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return (ctx->res_w == RES_SNTX);
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}
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}
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glob_target = &child->glob_result;
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if (child->argv)
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flags |= GLOB_APPEND;
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glob_target = &child->argv;
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}
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gr = xglob(dest, flags, glob_target);
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gr = xglob(dest, glob_target);
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if (gr != 0) {
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debug_printf_parse("done_word return 1: xglob returned %d\n", gr);
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return 1;
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@ -2954,14 +3002,17 @@ static int done_word(o_string *dest, struct p_context *ctx)
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b_reset(dest);
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if (ctx->pending_redirect) {
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if (ctx->pending_redirect->glob_word
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&& ctx->pending_redirect->glob_word[0]
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&& ctx->pending_redirect->glob_word[1]
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) {
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/* more than one word resulted from globbing redir */
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ctx->pending_redirect = NULL;
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if (glob_target->gl_pathc != 1) {
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bb_error_msg("ambiguous redirect");
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debug_printf_parse("done_word return 1: ambiguous redirect\n");
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return 1;
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}
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} else {
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child->argv = glob_target->gl_pathv;
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ctx->pending_redirect = NULL;
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}
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#if ENABLE_HUSH_LOOPS
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if (ctx->res_w == RES_FOR) {
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@ -3006,7 +3057,7 @@ static int done_command(struct p_context *ctx)
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/*child->argv = NULL;*/
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/*child->is_stopped = 0;*/
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/*child->group = NULL;*/
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/*child->glob_result.gl_pathv = NULL;*/
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/*child->glob_result = NULL;*/
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child->family = pi;
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//sp: /*child->sp = 0;*/
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//pt: child->parse_type = ctx->parse_type;
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